Sleep training

Okay so I have a 6 month old. He will be 7 months on the 28th.. he is in the habit of me holding him and rocking him to sleep. As soon as I lay him down he wakes right up and cry’s till I pick him up and rock him again, he also sleeps with me at night because he will not sleep in his crib. He used to fall asleep on his own and sleep in his crib all night, waking once to eat. Now he refuses to sleep in there. So today for naps I made him fall asleep on his own without me holding and rocking him. It took 5-10 minutes of whining/crying but he fell asleep. Now he’s in his crib and been in there for an hour so far and still is not sleeping. He was just in there playing and rolling around, now he’s crying and has been for about 5 minutes. I’m not sure how to go about getting him to sleep in his crib again. I want him out the habit of me holding him, rocking him to sleep, and sleeping with me at night time. I’ve been going in there patting his butt and telling him I love him but it’s time to go night night. I want him to learn how to self soothe.

Any tips?

FTM btw